1. Field of the Invention
The present invention relates to a toner container and a developer replenishing device to be detachably installed in an image forming apparatus in order to replenish a developing device built-in the image forming apparatus such as a copying machine, a printer, a facsimile machine, and the like with toner.
2. Description of the Related Art
A toner container disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2003-280344 is known as prior art. This toner container is detachably installed in a developing device in order to replenish the developing device built-in an apparatus main body of an image forming apparatus with toner. More specifically, the toner container replenishes the developing device with toner when an amount of toner within the developing device becomes less than the preliminary set amount.
Such a toner container includes a box-like container to be charged with toner, a toner conveyance screw provided at a bottom of this container in order to replenish the container with toner to further replenish the developing device, an agitating member for agitating toner within the container, and a cylindrical shutter member rotationally provided at an appropriate location of the toner container along an outer peripheral surface of the toner conveyance screw. The shutter member is rotatable around the cylinder axis between a closed position where the shutter is closed and an open position where the shutter is open. The agitating member includes an agitating shaft provided in parallel with the toner conveyance screw and an agitating blade integrally rotatably mounted to the agitating shaft.
When the toner container is slidably installed to the developing device, the rotational shutter member rotates from the closed position to the open position due to an interference with some member of the developing device to allow a passage between an inside of the toner container and an inside of the developing device. Accordingly, the developing device is replenished with toner from the container by a driving force of the toner conveyance screw through a refill opening of the container.
To the contrary, when the toner is removed from the developing device in order to exchange an old one for an new one, the rotational shutter member rotates in a backward direction (namely, from the open position to the closed position) to close the shutter member by release of the rotational shutter member from the interference (i.e., an interference opposite to the former interference is applied), thereby preventing the residual toner within the container from leaking to the outside.
On the other hand, the toner container disclosed in the Japanese Unexamined Patent Publication No. 2003-280344 includes the toner conveyance screw disposed only adjacent to a center of the container in a longitudinal direction. Therefore, it is not possible for toner residing outside both ends of the toner conveyance screw to head to a replenishing opening and thus it is hard to push the toner away so as not for the toner to stay within the container.
In order to place the toner conveyance screw almost the center of the container in the longitudinal direction, there is such an inconvenience that the toner conveyance screw needs to be rotatably supported on the container and thus it is hard to keep a stable supporting state of the toner conveyance screw. Further, in order to assemble the toner conveyance screw in the container, since the toner conveyance screw should be rotatably supported by a predetermined bearing member after the toner conveyance screw is once placed in the container, there is such a problem that an assembling operation becomes hard.